Environmental Risk and Uncertainty: Insights from Yucca Mountain

Abstract This study examines the effects of the risk from transporting high–level radioactive waste to the proposed Yucca Mountain repository on housing location decisions in Southern Nevada. Using data from a survey of southern Nevada households, we develop a model–based subjective risk estimate for each household. We then explore different factors that may influence the household's location decisions if the proposed transportation route is ultimately chosen for nuclear waste transport. We extend the conventional expected utility model to allow for uncertainty surrounding the actual risks borne by the household. Finally, we examine the impact of federal government compensation on households' location decisions. The findings indicate that residents currently living near the proposed transportation route express subjective risk estimates much larger than those reported by the Department of Energy. In general, households that are uncertain about the future risks are more likely to relocate than those expressing certainty. When everything is considered, the model predicts that between one and three percent of households living near the transportation route are likely to relocate. Compensation can influence some households to remain at their present location and bear the transport risk.     

Welfare and the Discriminating Public: Evaluating Entitlement Attitudes in Post-Communist Europe

Although post-communist Europe retains elements of its socialist past, public opinion shows discernment in its welfare preferences. This analysis of post-communist social welfare attitudes finds that post-communist societies are selective in their support for social policies. First, welfare preferences center on two underlying realms: government responsibility and government spending; and second, welfare opinions and beliefs are not uniform across several social policies. Although many of the conclusions highlight the selective nature of these preferences, the example of the support for unemployment benefits points to how the transition from communist-era welfare states to capitalist-led assistance continues to influence public opinion in these countries.     

The fish of Lake Titicaca: implications for archaeology and changing ecology through stable isotope analysis

Research on past human diets in the southern Lake Titicaca Basin has directed us to investigate the carbon and nitrogen stable isotopes of an important dietary element, fish. By completing a range of analyses on modern and archaeological fish remains, we contribute to two related issues regarding the application of stable isotope analysis of archaeological fish remains and in turn their place within human diet. The first issue is the potential carbon and nitrogen isotope values of prehistoric fish (and how these would impact human dietary isotopic data), and the second is the observed changes in the fish isotopes through time. Out of this work we provide quantitative isotope relationships between fish tissues with and without lipid extraction, and a qualitative analysis of the isotopic relationships between fish tissues, allowing archaeologists to understand these relationships and how these values can be applied in future research. We test a mathematical lipid normalization equation to examine whether future researchers will need to perform lipid extraction procedures for Lake Titicaca fish. We also analyze a number of aquatic plants to better understand the range of isotopic signatures of the Lake Titicaca ecosystem. We use these data to better understand prehistoric human diet and the role that fish may have played in the past as well as potential changes in local lake ecology through time.     

An experimental micromorphological investigation of bedding construction in the Middle Stone Age of Sibudu,South Africa

We conducted experiments to compare the micromorphological signatures of modern burnt sedge and grass bedding to laminated layers of carbonized material and phytoliths in Middle Stone Age deposits at the shelter, Sibudu. The experiments were designed to clarify the formation processes associated with the laminated layers and to investigate whether these previously identified layers of bedding were deliberately burned or not. The results indicate that the laminated layers were most likely produced by human activity related to the construction, maintenance and burning of bedding. Furthermore, our experiments demonstrate that large volumes of vegetal material could have produced the relatively thin, archaeological deposits of burnt bedding.     

Influence of seabird guano and camelid dung fertilization on the nitrogen isotopic composition of field-grown maize (Zea mays)

Organic fertilizers have the capacity to alter the nitrogen isotopic composition of plants. Camelid dung and seabird guano are two potentially important fertilizers in the agricultural systems of western South America, particularly Peru and Chile. This paper presents isotopic data (δ¹³C and δ¹⁵N) from field grown plants (maize, Zea mays) fertilized with the following four treatments: CO (control, no fertilizer applied), AS (ammonium sulfate, a chemical fertilizer), DU (camelid dung), and SG (seabird guano). Plants were grown in experimental plots in the Virú Valley, northern Peru. Plants fertilized with the chemical fertilizer presented very similar isotopic compositions compared to the control. Conversely, the camelid dung fertilized plants were characterized by higher δ¹⁵N values compared to the control plants (by 1.8 to 4.2‰ depending on the plant part). The seabird guano fertilized plants were greatly enriched in ¹⁵N in comparison to the control plants (by 11.3 to 20.0‰). The results of this study have important implications for the reconstruction of human diet using isotopic data derived from bone collagen and related tissues, particularly in the prehispanic Andes, but also in Europe and North America during the 19th century, when Peruvian seabird guano was used extensively. Specifically, the interpretation of the relative contributions of plant and animal protein to the diet on the basis of bulk isotopic compositions of bone collagen (or similar tissues) may be confounded by camelid dung fertilization if the carbon isotopic compositions of the two sources are similar. Likewise, the interpretation of the relative contributions of maize and marine protein may be confounded by seabird guano fertilization.